2002 Isuzu NPR with a chevy 5.7 and a 700R4 trans. same engine and tran as the 1 ton van. when cold it shifts properly but when it gets to operating temp when it up shifts. its so hard that it will lift the front of the truck and snap your head.
First, see what changing the transmission fluid and filter will do. Check your maintenance manual for any periodic transmission adjustments. If these things don’t help, you need a transmission specialist. To let it go, could cause expensive damage.
I think you have an exhaust leak if you believe the front end is lifting off the ground in 4th gear. Too many fumes doode!
Tell us more about your 700R4. Who built it and to what specs? Who set it up on the vehicle? Have you re-checked the TV cable adjustment? What rpms are the shift points at now?
I was able to get the front end of my 74 Chevy Luv (Isuzu) off the ground. I went and got a yard of topsoil. When I reached 35mpg…I could turn the wheel without having any effect on the direction of the truck.
I’ve done all that and the trans shop has no idea. ran a scsaner no code I did change the fluid and put some trans med in it that helped when is cold it shifts normal i think there is a control problem
I’ve done all that and the trans shop has no idea. ran a scsaner no code I did change the fluid and put some trans med in it that helped when is cold it shifts normal i think there is a control problem
Its never been into and there is no exhust leaks. a heavy loaded cab over box truck thats why it will lift.
Your NPR has a 4L80E in it. If the trans shop is finding no codes then they need to start checking line pressure readings…
transman